Jumper arrangement for overhead transmission lines

ABSTRACT

In a jumper arrangement for an overhead electric power transmission line wherein conductors of the transmission line are secured to a power transmission tower through strain insulator string assemblies and conductors on the opposite sides of the tower are electrically interconnected by a jumper conductor, main parts of the jumper conductor are formed by a rigid jumper rod and each end of the jumper rod is connected with a supporting fixture interposed between the conductor of the transmission line and the strain insulator string assembly through a pivotally connected supporting means. The jumper rod is further connected to the conductor of the transmission line through at least one electroconductive flexible connecting wire.

United States Patent [72] Inventors Akira Otsuki;

Kimikazu Numata, both of Tokyo, Japan [21] Appl. No. 64,735 [22] FiledAug. 18, 1970 [45] Patented Nov. 30, 1971 [73] Assignee The FujikuraCable Works, Ltd. Tokyo, Japan [32] Priorities Aug. 27, 1969 [33] Japan[31] 44/80782;

Aug. 28, 1969, Japan, No. 44/81225 [54] JUMPER ARRANGEMENT FOR OVERHEADTRANSMISSION LINES 10 Claims, I 1 Drawing Figs.

[52] US. Cl 174/43 [51] Int. Cl 02g 7/00 [50] Field of Search 174/40 R,43,45 R, 126 CP, 131 R; 191/40, 41;248/58,63; 339/222 [56] ReferencesCited UNITED STATES PATENTS Stone t.

Primary Examiner Laramie E. Askin AltomeyFlynn & F rishauf ABSTRACT: Ina jumper arrangement for an overhead electric power transmission linewherein conductors of the transmission line are secured to a powertransmission tower through strain insulator string assemblies andconductors on the opposite sides of the tower are electricallyinterconnected by a jumper conductor, main parts of the jumper conductorare formed by a rigid jumper rod and each end of the jumper rod isconnected with a supporting fixture interposed between the conductor ofthe transmission line and the strain insulator string assembly through apivotally connected supporting means. The jumper rod is furtherconnected to the conductor of the transmission line through at least oneelectroconductive flexible connecting wire.

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FIGiO FIGH JUMPER ARRANGEMENT FOR OVERHEAD TRANSMISSION LINES Thisinvention relates to a jumper arrangement for overhead electric powertransmission lines.

Prior jumper arrangements for a single or multibundle conductor overheadelectric power transmission line are usually made of a wire of the sametype as the conductors strung in spans and are mounted on a powertransmission tower to have a desired insulation distance from the tower.For example, a predetermined length of a jumper wire is cut at theconstruction site, jumper sockets are fitted under pressure to the opposite ends of the jumper wire, and the jumper sockets are connected toanchor clamps secured to the ends of the line conductors. However, thismethod of mounting involves many problems regarding the workability,saving of the cost, accuracy of the dimension, etc.

Although the clearances or spaces between the jumper wire and the toweror its arms are determined by considering the sag length of the jumperwire, the swinging movement of the jumper wire or the other movements ofthe power transmission line, it is essential to decrease as far aspossible these clearances in order to decrease the size of the jumperdevice and the tower itself.

To this end, it is desirable to firmly secure the jumper wire or toconstruct it as a perfectly rigid body so as to prevent swingingmovement or other movements from occurring. However, it is notpermissible to firmly secure the jumper wire to the conductors or toconstruct the jumper wire as the perfect rigid body merely for thepurpose of preventing the swinging movement or other movements, becausethe jumper wire is required to move in response to the variation in thecatenary angle of the conductor and insulator string caused bytemperature variations and various movements of conductor and insulatorstrings such as sleet-jump and galloping.

For this reason, it has been considered to manufacture the jumperarrangement in a factory, thus eliminating the field work of cutting thejumper wire to desired length as well as securing the jumper sockets.Such a prefabricated jumper arrangement can be fitted to thetransmission conductors supported by the tower by means of bolts andnuts. Furthennore, it is highly desirable to provide an economical butefficient jumper arrangement capable of efficiently preventing theswinging movement of the jumper wire as well as the movement thereof dueto uplift wind load and which in addition is readily capable offollowing the variation in the catenary angle of the conductor andinsulator string, while maintaining a small clearance between the jumperwire and the tower.

It is an object of this invention to provide an improved jumperarrangement including a rigid jumper rod which can be cut andmanufactured in a factory to have a desired length determined by theline angle or catenary angle thus simplifying the mounting operation atthe construction site.

Another object of this invention is to provide an improved jumperarrangement capable of withstanding swinging movement as well as themovement of the conductor of the transmission line caused by uplift windload, icing and so on.

A further object of this invention is to provide an improved jumperarrangement capable of following variations in the catenary angle of theconductor and insulator string caused by temperature variations andvarious movements of the conductor and insulator strings.

Another object of this invention is to provide an improved jumperarrangement including means to adjust the length of the connecting wirethus facilitating the mounting work of the jumper arrangement.

According to this invention there is provided a jumper arrangement foran overhead electric power transmission line of the type whereinconductors of the transmission line are secured to a power transmissiontower through strain insulator string assemblies and the ends of theconductors on the opposite sides of the tower are electricallyinterconnected by a jumper conductor, said jumper arrangement beingcharacterized in that the jumper conductor takes the form of a rigidjumper rod, and that each end of the jumper rod is connected with asupporting fixture interposed between the conductor of the transmissionline and the strain insulator string assembly through a pivotallyconnected supporting means and to the conductor of the transmission linethrough at least one electroconductive flexible jointing wire.

In the drawings:

FIG. 1 is a side view of the jumper arrangement after it has beensecured to a power transmission tower and conductors of an electricpower transmission line;

FIG. 2 is an enlarged side view of a portion of the jumper arrangementshown in FIG. 1;

FIG. 3 shows a cross section of one example of a jumper rod utilized inthe jumper arrangement;

FIG. 4 shows a cross section of a modified jumper rod;

FIG. 5 shows a cross section of another example of jumper rod;

FIG. 6 is a side view of a modified jumper arrangement after it has beensecured in position;

FIG. 7 is an enlarged view to show the construction of the jointsbetween the jumper rod, supporting means and connecting wires shown inFIG. 6;

FIG. 8 is a side view of another embodiment of this invention;

FIG. 9 is an enlarged side view of a portion of the embodiment shown inFIG. 8;

FIG. 10 is an enlarged side view, partly in section, of an adjustingfixture for adjusting the length of the supporting means adapted tosupport the jumper rod shown in FIG. 8; and

FIG. 11 is a sectional view taken along the line XI-XI in FIGS. 8 and 9and viewed in the direction of arrows.

With reference now to the drawings, in the embodiment shown in FIGS. 1and 2, there is provided a horizontal jumper rod 1 consisting of analuminum pipe, for example. The jumper rod is cut into a predeterminedlength in a factory by taking into consideration various factorsencountered in the construction site. The opposite ends of the jumperrod are supported by yoke plates or fittings 3 through supporting means2. As best shown in FIG. 2, each end of the jumper rod 1 is connectedwith the lower end of a supporting means 2 through a link 4 pivotallyconnected to these means. One end of each fitting 3 is connected with anarm 7 secured to a tower 6 through a strain insulator string assembly 5while the other end of the fitting 3 is connected with one end of mainconductors ll successively through a yoke 8, sector shaped yoke plates 9and anchor clamps 10. Further, each end of the jumper rod 1 is connectedto the ends of the main conductors 11 through flexible connecting wires12. The lower ends of flexible connecting wires 12 are connected to oneend of the jumper rod 1 by connecting element 13 while the upper endsare connected to anchor clamps 10. Two connecting wires 12 are heldspaced apart by means of a spacer 14.

As shown in FIG. 3, the jumper rod 1 may be comprised by a hollowtubular rod of rigid conductive material such as aluminum for example.Alternatively the jumper rod 1 may be comprised by a composite conductorincluding an outer aluminum pipe 1 and an inner iron pipe 40 as shown inFIG. 4 or a modified composite conductor including an aluminum pipe I, ahelical core 30 of an iron strip contained in aluminum pipe 1 and anouter layer of stranded aluminum conductors 31.

Since the jumper rod 1 has sufficient rigidity it will not sag and canprevent swinging movement or other movements. For this reason, it ispossible to always maintain constant clearances between the jumper rodand the tower as well as between said rod and the tower arm. In otherwords, even with a relatively small clearance between the jumper rod andthe tower or its arm, there is no fear of shortening between the towerand the jumper rod thus enabling to reduce the size of the tower andjumper rod. Longitudinal movement of the jumper rod 1 permitted by theuse of pivotally connected link 4 and flexible connecting wires 12permits the connection between the jumper rod and main conductors tofollow the variation in the catenary angle of the strain insulatorstring assembly 5 and main conductors 11 caused by temperature variationand the aforementioned movements of conductor and insulator strings suchas sleet-jump and galloping, thus preventing excessive impulsive shockfrom being applied to the jumper rod 1.

Since connecting wires 12 connected between main conductors l1 andjumper rod 1 are flexible, a slight difference in the length of thejumper rod is permissible, thus enabling cutting of the jumper rod inthe factory without regarding the accurate length of the jumper rod.This greatly saves work in the construction site.

FIG. 6 shows a modified embodiment of this invention wherein the lengthof the jumper rod is especially made small for the convenience oftransportation. In this case supporting means are mounted at inclinedpositions, and two spacers 14 are used to reinforce connecting wires 12.Other component parts are designated by the same reference numerals asin FIG. I so that their description is believed unnecessary.

FIG. 7 illustrates a modified branched socket 13' including a socket arm15 on one side for receiving the jumper rod 1 and a pair socket arms 16on the opposite side for receiving connecting wires I2. The upper end ofthe socket 13' is pivotally connected to the lower end of the supportingmeans 2 through link 4.

FIGS. 8 and 9 show still another modification of this invention which issubstantially identical to the previous embodiments except that avernier-type length adjuster 17 is inserted at an intermediate point ofeach supporting means 2.

As shown in FIG. the length adjuster 17 comprises a strip-shapedconnecting member 19 provided with a number of equally spaced-apartopenings 18, a U-shaped connecting member 21 having two legs sandwichingthe connecting member 19 and provided with a plurality of openings 20 ofa pitch different from that of openings 18, a bolt 22 extending througha selected pair of openings 18 and 20 and a nut 23.

The jumper rod 1 and connecting wires 12 are interconnected in thefollowing manner. A flange 25 with a plurality of openings 24, as shownin FIG. 11 is secured to one end of the jumper rod 1, and a cylindricalsleeve 26 is press-fitted about the gathered ends of two connectingwires 12. The sleeve 26 is integrally formed with flange 27 having aplurality of openings 28 aligned with openings 24 in flange 25, andthese flanges 25 and 27 are connected by bolts 29 extending throughaligned openings 24 and 28.

The embodiment shown in FIGS. 8 and 9 provides the same advantages asthose of the embodiment shown in FIGS. 1 and 2. Further, according tothe embodiment shown in FIGS. 8 and 9 it is possible to adjust thelength of the supporting means so as to adjust the horizontality and thelevel of the jumper rod, thus correctly maintaining it in the desiredposition.

What we claim is:

I. In a jumper arrangement for an overhead electric power transmissionline wherein conductors of the transmission line are secured to a powertransmission tower through strain insulator string assemblies and theends of said conductors on opposite sides of said tower are electricallyinterconnected by a jumper conductor, the improvement which comprises arigid jumper rod forming said jumper conductor, supporting fixturesinterposed between said conductors of the transmission line and saidstrain insulator string assemblies, a pair of supporting means, eachincluding a rigid element connecting respective ends of said rigidjumper rod to one of said supporting fixtures for suspending said rigidjumper rod from said transmission line, and an electroconductiveflexible connecting wire connecting each end of said rigid jumper rod toits respective conductor of the transmission line.

2. The jumper arrangement according to claim 1 wherein a link mechanismpivotally connects each end of said rigid jumper rod and said respectivesupporting means to enable said jumper rod to be displaced.

3. The jumper arrangement according to claim 2 wherein said rigidelements of said supporting means are arranged substantially vertical.

4. The umper arrangement according to claim 2 wherein said rigidelements of said supporting means are arranged on an inclined plane.

5. The jumper arrangement according to claim 1 wherein at least one ofsaid supporting means includes adjusting means for adjusting thehorizontality and the level of said rigid jumper rod.

6. The jumper arrangement according to claim 5 wherein said at least onesupporting means includes a rigid member having an adjustable length foradjusting the horizontality and level of said rigid jumper rod.

7. The jumper arrangement according to claim 5 wherein said adjustingmeans comprises a strip-shaped connecting member having a number ofequally spaced-apart openings therein, a U-shaped connecting memberhaving two legs sand: wiching said strip-shaped connecting member andbeing provided with a plurality of openings spaced differently from saidspaced openings in said strip-shaped connecting member, and a lockingmember for selectively locking one of said openings of said strip-shapedconnecting member and one of said openings of said U-shaped connectingmember.

8. The jumper arrangement according to claim 5 wherein a link mechanismpivotally connects each end of said rigid jumper rod and said respectivesupporting means to enable said jumper rod to be displaced.

9. The jumper arrangement according to claim 8 wherein said at least onesupporting means includes a pair of rigid elements, each pivotallyconnected to an end of said rigid jumper rod and each pivotallyconnected to one of said supporting fixtures, each of said rigidsupporting elements including means for adjusting the length thereof foradjusting the horizontality and level of said rigid jumper rod.

10. The jumper arrangement according to claim 1 wherein said supportingfixtures include means for pivotally connecting said conductors of saidtransmission line to said strain insulator string assemblies.

1. In a jumper arrangement for an overhead electric power transmissionline wherein conductors of the transmission line are secured to a powertransmission tower through strain insulator string assemblies and theends of said conductors on opposite sides of said tower are electricallyinterconnected by a jumper conductor, the improvement which comprises arigid jumper rod forming said jumper conductor, supporting fixturesinterposed between said conductors of the transmission line and saidstrain insulator string assemblies, a pair of supporting means, eachincluding a rigid element connecting respective ends of said rigidjumper rod to one of said supporting fixtures for suspending said rigidjumper rod from said transmission line, and an electroconductiveflexible connecting wire connecting each end of said rigid jumper rod toits respective conductor of the transmission line.
 2. The jumperarrangement according to claim 1 wherein a link mechanism pivotallyconnects each end of said rigid jumper rod and said respectivesupporting means to enable said jumper rod to be displaced.
 3. Thejumper arrangement according to claim 2 wherein said rigid elements ofsaid supporting means are arranged substantially vertical.
 4. The jumperarrangement according to claim 2 wherein said rigid elements of saidsupporting means are arranged on an inclined plane.
 5. The jumperarrangement according to claim 1 wherein at least one of said supportingmeans includes adjusting means for adjusting the horizontality and thelevel of said rigid jumper rod.
 6. The jumper arrangement according toclaim 5 wherein said at least one supporting means includes a rigidmember having an adjustable length for adjusting the horizontality andlevel of said rigid jumper rod.
 7. The jumper arrangement according toclaim 5 wherein said adjusting means comprises a strip-shaped connectingmember having a number of equally spaced-apart openings therein, aU-shaped connecting member having two legs sandwiching said strip-shapedconnecting member and being provided with a plurality of openings spaceddifferently from said spaced openings in said strip-shaped connectingmember, and a locking member for selectively locking one of saidopenings of said strip-shaped connecting member and one of said openingsof said U-shaped connecting member.
 8. The jumper arrangement accordingto claim 5 wherein a link mechanism pivotally connects each end of saidrigid jumper rod and said respective supporting means to enable saidjumper rod to be displaced.
 9. The jumper arrangement according to claim8 wherein said at least one supporting means includes a pair of rigidelements, each pivotally connected to an end of said rigid jumper rodand each pivotally connected to one of said supporting fixtures, each ofsaid rigid supporting elements including means for adjusting the lengththereof for adjusting the horizontality and level of said rigid jumperrod.
 10. The jumper arrangement according to claim 1 wherein saidsupporting fixtures include means for pivotally connecting saidconductors of said transmission line to said strain insulator stringassemblies.